May 9 / Cody Winniford

HemoDIEnamics Part 2

In part 1 I talked about catching shock early and making your big move before the patient loses their ability to compensate (and perhaps respond to resuscitation). Perhaps there is more to say about it rather than saying things like “aggressive” and “ big move.” Can you be too aggressive? Sure, there are a few clinical contexts where you can overshoot or push it too hard too fast. So to that point I’ve got a graduated response scheme for part 2.

The whole point of this series is to shift the mindset from looking for vitals to seeing the physiology, and acting on that physiology, in the compensated phase, so that the patient can stabilize and compensate longer. Ultimately, with the goal of surviving to the OR and beyond.

My Mindsets:
 - Occult shock isn’t really occult if you know what to look for. 
 - Shock is shock, no matter what descriptor you put in front of it. Compensated or decompensated… it’s still SHOCK.  

Here is how I approach it:

Phase 1: Identification of Occult Shock (The "Yellow"Zone)
The patient appears "stable" with a MAP > 65, but compensation is maxed. I don’t wait for shock to “show up.” I assume that it is there and I look for the cause. The numbers are there to support my assumption and guide me to look in certain places for problems I can fix. 

Being successful in making things look better here does not mean that you wont have to escalate things later. 

Clinical Indicators:
 • Narrowing Pulse Pressure: < 30
 • Rising Shock Index: 0.7 —> 0.9
 • Trending EtCO2: A continuing downward trend without a respiratory etiology to cause it gets my attention. 
 • Physical Exam: Cool extremities, delayed capillary refill, anxious or restless behavior

Proactive Work:
 1. Hemorrhage Control: Immediate reassessment of TQs, wound packing, or pelvic binders. Perhaps even unwrapping that AAJT and placing it.  
 2. Volume Optimization and Hemostatic Resus: Blood (if traumatic in nature), fluids if another cause of hypovolemia is suspected. TXA and perhaps some Ca+ if hemorrhage is the problem. Use volume to stabilize them as long as they are volume responsive. See: pulse pressure notes.

Buy back as much time as possible here, because once they turn that corner, it will be difficult to turn them around without much more volume than you have on hand. 

Phase 2: Impending Hemodynamic Collapse (The "Red" Zone)
Compensation has failed. They have either a.) run out of volume. OR b.) run out of endogenous catecholamines. Either way, you have your hands full. The resuscitation turns away from volume replacement and deliberately addressing causes of traumatic arrest and/or restoring forward flow of oxygenated blood. You have to move quickly, after 10:00 in this phase, hemodynamic collapse is a near certainty. 

Clinical Indicators:
 • Pathological Pulse Pressure: Either severely narrow (20) or widening with a crashing DBP (< 60 mmHg).
 • Shock Index: > 1.0
 • EtCO2: < 25 
 • The "Peri-Arrest" Threshold: SI > 1.0 + EtCO2 < 25. = 5:00 to take decisive, deliberate action… or make a big move.

HOTT Drill

When the patient's vitals near or cross these thresholds we have to take deliberate action. The HOTT drill comes from the trauma arrest literature that identifies hemorrhage, hypoxia, tension pneumothorax, and cardiac tamponade as the potentially reversible causes of cardiac arrest from trauma. So if they’re reversible causes of arrest, then it simply makes sense to address them in the peri-arrest state. The HOTT drill should take no more than 5:00 to complete, the goal of which is to prevent an arrest. 

 1. Hypovolemia/hemorrhage:
 One or two units is likely not going to get the patient out of trouble. 4-6 units is a better starting point if you have it. Reluctant to mention it here, but crystalloid may be all there is to provide volume to the patient and keep the heart going. I would rather accept the risks of using crystalloid and keep the heart pumping than try to restart a heart in arrest from hypovolemia. 
 2. Oxygen:
 The airway is not the star of the show, but it has to be addressed… in a manner that poses the least amount of risk to impacting the hemodynamics. In my opinion, place an SGA and continue the resuscitation. Tube them after they have been stabilized to the degree they can physiologically support the procedure. The ventilation strategy has to be tight as well. 
 3. Tension Pneumothorax/Tamponade:
 You must deliberately rule these out. Ultrasound is an incredibly important tool to have in this situation. I am not sure that empirically decompressing the chest and performing a pericardiocentesis is the right thing to do, simply because I cannot back that up with literature. Having said that, perhaps it does make sense to maintain a high index of suspicion(based on clinical assessment and the story), and make a move based on those findings. Perhaps even lowering your threshold for action makes some sense. 


The Punchline

The punchline of this one is that there is a window of opportunity in which deliberate action can keep the patient from arresting. If you seize and maintain the initiative with the right actions at the right time, you have a better chance of staving off a deep and profound shock state.  



References:

(Google Gemini was used to assist with the formatting and referencing of this article. At Pulse Check, we believe in high quality education. We sometimes use AI to help synthesize massive amounts of clinical data and to help structure our layouts, but every clinical take, every 'deep-dive' analogy, and every final word is vetted and written by a human paramedic. We use the tech so we can spend more time on the medicine. The conclusions here are wholly our own.)


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